/*
MIT License

Copyright (c) 2020 www.joolun.com

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
package com.atguigu.paymentdemo.util;

import org.apache.commons.lang3.ArrayUtils;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;

/**
 * 文件处理工具类
 *
 * @author ruoyi
 */
public class FileUtils extends org.apache.commons.io.FileUtils
{
	public static String FILENAME_PATTERN = "[a-zA-Z0-9_\\-\\|\\.\\u4e00-\\u9fa5]+";

	/**
	 * 输出指定文件的byte数组
	 *
	 * @param filePath 文件路径
	 * @param os 输出流
	 * @return
	 */
	public static void writeBytes(String filePath, OutputStream os) throws IOException
	{
		FileInputStream fis = null;
		try
		{
			File file = new File(filePath);
			if (!file.exists())
			{
				throw new FileNotFoundException(filePath);
			}
			fis = new FileInputStream(file);
			byte[] b = new byte[1024];
			int length;
			while ((length = fis.read(b)) > 0)
			{
				os.write(b, 0, length);
			}
		}
		catch (IOException e)
		{
			throw e;
		}
		finally
		{
			if (os != null)
			{
				try
				{
					os.close();
				}
				catch (IOException e1)
				{
					e1.printStackTrace();
				}
			}
			if (fis != null)
			{
				try
				{
					fis.close();
				}
				catch (IOException e1)
				{
					e1.printStackTrace();
				}
			}
		}
	}

	/**
	 * 删除文件
	 *
	 * @param filePath 文件
	 * @return
	 */
	public static boolean deleteFile(String filePath)
	{
		boolean flag = false;
		File file = new File(filePath);
		// 路径为文件且不为空则进行删除
		if (file.isFile() && file.exists())
		{
			file.delete();
			flag = true;
		}
		return flag;
	}

	/**
	 * 文件名称验证
	 *
	 * @param filename 文件名称
	 * @return true 正常 false 非法
	 */
	public static boolean isValidFilename(String filename)
	{
		return filename.matches(FILENAME_PATTERN);
	}

	/**
	 * 检查文件是否可下载
	 *
	 * @param resource 需要下载的文件
	 * @return true 正常 false 非法
	 */
	public static boolean checkAllowDownload(String resource)
	{
		// 禁止目录上跳级别
		if (StringUtils.contains(resource, ".."))
		{
			return false;
		}

		// 检查允许下载的文件规则
		if (ArrayUtils.contains(MimeTypeUtils.DEFAULT_ALLOWED_EXTENSION, FileTypeUtils.getFileType(resource)))
		{
			return true;
		}

		// 不在允许下载的文件规则
		return false;
	}

	/**
	 * 下载文件名重新编码
	 *
	 * @param request 请求对象
	 * @param fileName 文件名
	 * @return 编码后的文件名
	 */
	public static String setFileDownloadHeader(HttpServletRequest request, String fileName) throws UnsupportedEncodingException
	{
		final String agent = request.getHeader("USER-AGENT");
		String filename = fileName;
		if (agent.contains("MSIE"))
		{
			// IE浏览器
			filename = URLEncoder.encode(filename, "utf-8");
			filename = filename.replace("+", " ");
		}
		else if (agent.contains("Firefox"))
		{
			// 火狐浏览器
			filename = new String(fileName.getBytes(), "ISO8859-1");
		}
		else if (agent.contains("Chrome"))
		{
			// google浏览器
			filename = URLEncoder.encode(filename, "utf-8");
		}
		else
		{
			// 其它浏览器
			filename = URLEncoder.encode(filename, "utf-8");
		}
		return filename;
	}

	/**
	 * 下载文件名重新编码
	 *
	 * @param response 响应对象
	 * @param realFileName 真实文件名
	 * @return
	 */
	public static void setAttachmentResponseHeader(HttpServletResponse response, String realFileName) throws UnsupportedEncodingException
	{
		String percentEncodedFileName = percentEncode(realFileName);

		StringBuilder contentDispositionValue = new StringBuilder();
		contentDispositionValue.append("attachment; filename=")
				.append(percentEncodedFileName)
				.append(";")
				.append("filename*=")
				.append("utf-8''")
				.append(percentEncodedFileName);

		response.setHeader("Content-disposition", contentDispositionValue.toString());
	}

	/**
	 * 百分号编码工具方法
	 *
	 * @param s 需要百分号编码的字符串
	 * @return 百分号编码后的字符串
	 */
	public static String percentEncode(String s) throws UnsupportedEncodingException
	{
		String encode = URLEncoder.encode(s, StandardCharsets.UTF_8.toString());
		return encode.replaceAll("\\+", "%20");
	}
}
